Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109, USA.
J Integr Plant Biol. 2013 Sep;55(9):835-46. doi: 10.1111/jipb.12077.
Root hairs and pollen tubes are formed through tip growth, a process requiring synthesis of new cell wall material and the precise targeting and integration of these components to a selected apical plasma membrane domain in the growing tips of these cells. Presence of a tip-focused calcium gradient, control of actin cytoskeleton dynamics, and formation and targeting of secretory vesicles are essential to tip growth. Similar to cells undergoing diffuse growth, cellulose, hemicelluloses, and pectins are also deposited in the growing apices of tip-growing cells. However, differences in the manner in which these cell wall components are targeted and inserted in the expanding portion of tip-growing cells is reflected by the identification of elements of the plant cell wall synthesis machinery which have been shown to play unique roles in tip-growing cells. In this review, we summarize our current understanding of the tip growth process, with a particular focus on the subcellular targeting of newly synthesized cell wall components, and their roles in this form of plant cell expansion.
根毛和花粉管通过顶端生长形成，这一过程需要合成新的细胞壁物质，并将这些成分精确靶向到这些细胞生长尖端的选定顶质膜域。存在一个聚焦于尖端的钙梯度、肌动蛋白细胞骨架动力学的控制，以及分泌小泡的形成和靶向，对顶端生长至关重要。与经历弥散生长的细胞类似，纤维素、半纤维素和果胶也沉积在顶端生长细胞的生长尖端。然而，细胞壁成分的靶向和插入方式的差异反映在已被证明在顶端生长细胞中发挥独特作用的植物细胞壁合成机制的元素的鉴定上。在这篇综述中，我们总结了我们目前对顶端生长过程的理解，特别关注新合成细胞壁成分的亚细胞靶向及其在这种植物细胞扩展形式中的作用。
